An Energy Management Strategy for Multistack Fuel Cell Hybrid Locomotives With Integrated Optimization of System Service Life

To extend the lifespan of hybrid locomotive multistack fuel cell systems (MFCSs) and ensure the consistency of multiple fuel cells (FCs), this article proposes an energy management strategy with integrated optimization of system service life (IOSL-EMS). The strategy first unifies the hydrogen consumption (HC) of the FC and the equivalent hydrogen consumption of the battery into quadratic polynomial frameworks. It then considers the service life consistency of multiple FCs and the battery state of charge (SOC) constraint as additional hydrogen consumption, constructing the comprehensive equivalent hydrogen consumption (CEHC) of the system. By analyzing the incremental form of CEHC, the quadratic programming method is used to minimize the CEHC increment, effectively allocating load power between the FCs and the battery. To verify the effectiveness of IOSL-EMS, a hardware-in-the-loop platform was built, and tests were conducted. Results show that IOSL-EMS effectively controls the service life consistency of multiple FCs while ensuring system economy. Compared to the existing rule-based state machine control strategy and optimization-based equivalent consumption minimization strategy, IOSL-EMS significantly extends the service life of the MFCS and reduces the equivalent hydrogen consumption of the hybrid locomotive. In addition, the proposed strategy has similar control capabilities to dynamic programming (DP).